Cheers! Nope defiantly not a Wahoo. We get them here too, and although they are very similar in Shape and size, the beast i'm holding is defiantly a Spanish Mackerel in Australia.

I did a bit of Googling and found a good pic of a Wahoo Seems as if the Wahoo has a more pronounced front fin. The fin that retracts up and down with all those spines (i don't think its called the dorsal fin).

The spanish Macks here have that but not as large.

My Spaniard could quite well be your Wahoo. None the less they all taste good!